Recently, with the development of the optical fiber sensing layer detecting technology, optical fiber sensing layers can be used to detected men's breaths, heartbeats, sleeps, etc., and has been gradually used into the field of house field, for example, baby cushions, seat cushions, etc.
For example, in a human breathing detecting mattress which has an optical fiber sensing layer, the appearance of mattress is a kit, the kit has an optical fiber sensing layer. The optical fiber sensing fiber includes an optical fiber and upper and lower layers of grids. The material of the grids is layer mesh material which is harder than the optical fiber. The optical fibers are arranged to be parallel with each other in the grid so as to form a sensing area. In this way, when a person lies on the mattress, as the person breathes, the upper and lower grid will be urged to press on the optical fiber and make the optical fibers deform differently. Luminance decays will happen when the optical fiber are bent, then the luminance decay values will be transmitted to an electronic assembly, through the mathematical calculation by the electronic assembly, related data about human breaths will be obtained.
However, because the optical fibers have the defects of being easy to be crushed or damaged, the upper and lower grids may prone to crush the optical fiber. During the arrangement of the optical fibers, the interval between adjacent optical fibers cannot be too small. Because of the limitation of the curvature characteristics of the optical fibers, normally the interval is at least 20 mm. If the interval is too small, the optical fiber may be broken; if the interval is too big, the deformation of the optical fiber may be unobvious when some areas of the grid are pressed, then the luminance decays will be affected. Thus, sensing blind areas may exist, which may lead to a non-uniform sensitivity of the optical fiber sensing layer and a big drop value. Besides, it further has these problems: when the same pressure acts on different sensing points of the same grid, there may be great differences between the sensitivities of different sensing points. In this way, it may cause that the breathing variation may not be detected and the upper and lower grids cannot be bent when a human body changes a posture on the sensing layer. If the grid bends, it is difficult for the optical fibers between the upper grid and the lower grids to detect the pressure from the sensing layer. Thus, the sensitivity of the optical fiber sensing layer may be decreased. Further, the thickness of the upper and lower grids must have certain thicknesses so as to make the optical fiber bend, the thicknesses cannot be adjusted according to various applications, and thus the application of the sensing layer is limited.